Suppress Wunreachable-code in floating matchers and exception tests

Closes #1350

projects/SelfTest/UsageTests/Exception.tests.cpp

@@ -18,6 +18,7 @@
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wweak-vtables"
 #pragma clang diagnostic ignored "-Wmissing-noreturn"
+#pragma clang diagnostic ignored "-Wunreachable-code"
 #endif
 
 namespace { namespace ExceptionTests {